1. Field of the Invention
The invention relates to a light emitting diode (LED) power supply device. Particularly, the invention relates to a smart LED power supply device controlled by a digital control device, which is capable of setting an output specification through programming.
2. Description of Related Art
Application of light emitting diode (LED) lamp is very wide, and a power supply device of the LED lamp has two implementations, where a first type constant current power supplying method is at that shown in FIG. 1, in which an input terminal of a power supply device 102 is connected to L and N poles of an alternating current (AC) power 101, and an output terminal thereof is coupled to An LED lamp 109. The power supply device 102 of the LED lamp 109 includes a constant voltage power supply system 104 and a constant current power supply system 107. The front-end constant voltage power supply system 104 includes a constant voltage power supply device 103 and a corresponding analog control device 105, and the back-end constant current power supply system 107 includes a constant current power supply device 108 and a corresponding analog control device 106, where an output terminal of the constant current power supply system 107 is connected to the LED lamp 109 for providing the required specific direct current (DC) current and voltage to the LED lamp 109. The constant current power supply system 107 and the LED lamp 109 are separated from each other.
A second type constant voltage power supplying method of the LED lamp is at that shown in FIG. 2, and an input terminal of the constant voltage power supply system 104 is connected to the L and N poles of the AC power 101, and an output terminal thereof is connected to the constant current power supply system 107. The constant voltage power supply system 104 includes the constant voltage power supply device 103 and the corresponding analog control device 105, and the constant current power supply system 107 includes the constant current power supply device 108 and the corresponding analog control device 106, where an output terminal of the constant current power supply system 107 is connected to the LED lamp 109 for providing the required specific DC current and voltage to the LED lamp 109. The constant current power supply system 107 and the LED lamp 109 are altogether installed inside a casing of the LED lamp 109 to form an integral device.
Both of the constant current and constant voltage LED power supply devices of the conventional technique have following shortages. The power supply devices have to be specifically designed and tested in allusion to different demands of input current and voltage of different LED lamps. Meanwhile, the existing LED lamps have a wide range of requirement for the input current and voltage, so that a production cycle of the existing LED power supply devices is relatively long, and cost thereof is relatively high.